1. Field of the Invention
This invention relates broadly to a food processing machine in which a food product workpiece is reciprocatingly displaced through a cutting blade. The invention more specifically relates to a mounting frame for the trays on which the food workpiece slides and the blade guide which guides the cutting blade. This invention additionally relates to a coupling for drivingly linking a rotary drive motor to a pulley in a food product slicing machine.
2. Description of the Related Art
Food processing machines form slices of food product by moving a food product workpiece through a blade. Examples of such machines are shown in U.S. Pat. No. 3,760,715 to Grote et al., and U.S. Pat. No. 4,436,012 to Hochanadel, which are incorporated by reference. In both of these machines, a food product retaining carriage is reciprocatingly displaced through a path which includes a slicing blade, such as the endless loop blade disclosed in U.S. Pat. No. 4,230,007 to Grote et al., which is incorporated by reference. As the food product is displaced through the blade, a thin slice is removed from the food product workpiece and falls downwardly from the blade. The machines can slice thousands of slices of meat, cheese, vegetables and other foods each day. Cleaning of all parts which contact the food is necessary at least once daily to prevent unacceptably high levels of bacteria on the machines.
The conventional method of cleaning food processing machines includes removing all easily detached parts for submersion cleaning in a bath, and high pressure spraying of the remaining parts. One portion of cutting machines which is particularly susceptible to food buildup, and is particularly difficult to clean, is the blade drive components. This includes a pair of pulleys around which the flexible, endless loop blade extends. Conventionally, one of the pulleys is an idler pulley which rotatably mounts to the frame of the machine by a roller bearing. The second of the pulleys is driven by an electric, rotary motor, the driveshaft of which is directly connected to the driven pulley by a spline shaft, for example. Removal of the pulley requires the removal of a nut from a threaded portion of the driveshaft. Reattachment after cleaning involves re-tightening the nut and adjusting the alignment of the pulley. Removal of the idler pulley is similarly difficult and requires hand tools which can be misplaced. Because it is difficult to remove the pulleys, they are not ordinarily detached for cleaning, but cleaned by merely directing a high-pressure spray onto and behind them to remove whatever food particles can be reached by the spray. This cleaning method can be ineffective unless care is taken to clean all surfaces.
Another region of the machine that is difficult to clean, and is additionally susceptible to relative shifting over a period of time, includes the trays on which the reciprocating food product workpiece rests. In the slicing machines discussed in the three referenced patents, there are three elements against which the lower end of the food product workpiece slides during reciprocating displacement of the workpiece. The thickness tray is a planar or curved surface which the workpiece rests upon at the beginning of the cutting cycle. The thickness tray is attached to the frame of the food product slicing machine. The machine frame is the portion of the machine that provides mounting support for most of the distinct, attached parts of the machine. This can be a skeleton of very sturdy, interconnected beams and bars, or a unit-body construction in which panels and sheets are connected to form the frame, such as in an automobile frame. The frame can also consist of a combination of the two types.
Also attached to the machine frame, and spaced slightly from one longitudinal end of the thickness tray to form a gap, is a blade guide. The blade guide has a slot formed along the entire length of the side nearest the gap. The endless loop blade is positioned in the blade guide slot and advanced continuously to slice food products which are brought into contact with the blade.
An upper, planar surface of the blade guide is flush (i.e. coplanar) with an upper, planar surface of a back tray. The back tray is rigidly mounted to the machine frame on the opposite side of the blade guide from the thickness tray. A food product workpiece initially rests on the thickness tray, and is displaced into the blade to remove a slice. The remaining part of the workpiece (directly above the slice) slides past the blade onto the upper surfaces of the blade guide and the back tray.
The thickness tray, back tray and blade guide are conventionally separately mounted to the machine frame by removable fasteners, such as bolts. These trays are cleaned by high pressure spray, or complete removal for submersion in a bath. Removing these parts is time consuming and requires tools, as with the pulleys in the conventional machine. Additionally, because the back tray, blade guide and thickness tray are all attached to the primary frame elements of the machine, any significant force applied to the machine frame can cause the trays and blade guide to become misaligned relative to one another. Misalignment will cause slices to be improperly formed. The force which misaligns the trays and blade guide can be a single, sudden impact, or repetitive vibratory forces applied over a long period of time.
Therefore, the need exists for a food product slicing machine having more easily removed parts, requiring few tools for disassembly and which reduces the problem of misalignment over time.